The invention concerns a photographic camera with a device producing an electric signal proportional to the relative motion between the object being sighted and the camera. The device comprises an evaluating circuit to receive said signal and to generate an output signal as a function of additional parameters. The output signal is fed to display and/or control means, which either indicate to the user of the camera that the exposure time is set too long for the relative motion existing between the camera and the object and/or serve to automatically set the shutter or the exposure time, respectively, of the camera in relation to said relative motion. The automatic shutter or exposure time control mechanism may be that as described in U.S. application Ser. No. 929,723, filed July 31, 1978, incorporated herein by reference.
The above cited patent application discloses as the means for generating a signal proportional to the relative motion between the camera and the object an imaging optical device, a stationary grating mounted at least in the vicinity of the image plane of said optical device and a photoelectric receiver system following in series. An additional prior art device showing a camera having means for generating an electrical signal proportional to the relative motion between the object sighted and the camera is found in U.S. Pat. No. 2,413,349, incorporated herein by reference.